Cutter blade attachment for excavator bucket



y 14, 1963 R. A. FLATH 3,089,261

CUTTER BLADE ATTACHMENT FOR EXCAVATOR BUCKET Filed June 21, 1961 \3 \4 Fl 6 INVENTOR.

Rev A. FLATH A FT 6. 5 WM mj g m,

A'r'roaNaY United States Patent 3,089,261 CUTTER BLADE ATTACHMENT FOR; EXCAVATOR BUIKET' Roy A. Flath, 9100 W. Herbert Court, Milwaukee, Wis. Filed June 21,1961, Ser. No. 118,570 7 Claims. (Cl. 37-118)- This invention relates to a cutter blade attachment for an excavator bucket and is specifically designed for use on a back hoe bucket for digging ditches.

Sewer and Water contractors are subject to ratherrigidspecifications as to the minimum and maximum width ditch for a given size pipe. Each different size pipe requires a ditch of different dimensions. Since a single contract may involve the installation of several different size pipes, a contractor must be able to excavate ditches of various size often requiring several changes in the course of a days work.

Prior to this invention the most commonly practiced methods for cutting ditches of various size were to either use buckets of different size and/or buckets adapted for use with cutter blades of various size which were changed each time a different size cut was to be made. To change buckets for each different size ditch is obviously a timeconsuming and costly approach. To change cutter blades is also time-consuming and, requires a number of different blades to take care of the wide range of widths involved.

In view of the foregoing, the principal object of this invention is to provide a cutter blade attachment of improved construction which may be quickly and readily adjusted to facilitate the cutting of ditches of many different widths without changing blades or buckets.

Another object is to provide cutters which in all adjusted positions will cause the loosened earth to be guided into the bucket as the cut is made to thus reduce the time it takes to remove the dirt from the ditch after it is cut by the bucket.

Another object is to provide cutters which will not interfere in any way with the discharge of the dirt from the bucket after a cut is made.

Another object is to provide cutters which can be inverted and reversed to opposite sides of the bucket when worn to. present a new cutting point and thereby double the life of the cutters.

Another object is to, provide cutters which make a smooth cut to provide straight walls in the ditch. .to facilitate installation of bracing required by safety regulations.

Antoher object is to provide cutters which are adapted for cutting manholes having curved sides to thereby great ly reduce the man hours formerly required to. do this job.

Another object is to provide a cutter blade which can be readily adjusted vertically to cut ditches having crosssecti'onal contours as, desired.

The objects of this invention are provided by a cutter attachment for an excavating bucket which includes a pair of mounting brackets fixedly secured to opposite sides of the bucket and a pair of cutter blades mounted on the brackets and adapted for making a cut having a width in excess of the bucket width. A hinge means including mating hinge barrels on the blades and brackets and a hinge pin mounted in the barrels isv provided for adjusting the position of the blades with respect to the brackets to. facilitate. making cuts of different widths without changing buckets or replacing the cutter blades. A lockingmeans including a plurality of adjusting; bolts mounted in opposing flanges on the blades and brackets is provided for fixing the blades at different angular positions with respect to the sides of the bucket. To change the adjustment the bolts are removed and different size spacers are installed between the opposing flanges on the blades and brackets.

Each of the blades is provided with a pairof spaced cutting points and a pair of deflector portions located rearwardly of the cutting points which serve to guide the loosened dirt into the bucket. Only one of the cutting points and deflector portions receives any appreciable wear when in use. The blades are adapted for reversal from one side of the bucket to the other so that when one set of points becomes worn the blades can be reversed and inverted to the other side of the bucket to provide a new set of points and thus double the life of the cutters.

Further refinements of the invention involve the mounting of the blades so that the opening of the bucket is completely unobstructed to facilitate a smooth entry and discharge of dirt therefrom.

Cutter blades made as described above when installed ona bucket 28 inches wide, for example, are capable of cutting ditches anywhere from 34 to 48 inches on a straight-line pull. Such cutters, when set at maximum width, will cut a ditch up: to 7 feet wide by crowding the cutters in the wall of the bank without moving the machine off the. center-line of the ditch and without the back of the bucket heeling into the wall. Thus a set. of cutters made in accordance with this. invention and installed on a. 28-inch bucket will facilitate. the cutting of ditches all the way-from 34 inches to 7 feet in width without moving the machine off the center-line of the ditch.

Other objects andadvantages will be pointed out in, or be apparent from the specification and claims, as will obvious modifications of the single embodiment shown in the drawings, in which:

FIG. 1- is a front elevation view of a back hoe bucket equipped with a, pair of cutter blades and mounting brackets constructed in accordance with my invention;

FIG. 2 is a side elevation view of the bucket and cutter blade attachments shown in FIG. 1;

FIG. 3 is a sectional view taken along line 3 3 of FIG. 1;

FIG. 4 is a sectional view taken along line 44 of FIG. 1;

FIG. 5 is a sectional view taken through a ditch cut by a back hoe bucket such as that shown in FIGS. 1, 2 and 3; and

FIG. 6 is aside. elevationview of a back hoe equipped with a bucket andv cutter blade, attachments of the type shown in FIGS. 1, 2 and, 3.

Referring now to the drawings in detail, FIG. 6 shows an excavating machine of the type commonly known asv a back hoe. While the cutter blade attachment of this invention may possibly be used on buckets of other types of excavating machines they are particularly adapted for use on the bucket of a back hoe such as that shown in FIG. 6

As shown in FIG. 1, a pair of cutter blades 19. are mounted on a back hoe bucket 12 by a pair of mounting brackets 14. Bucket 12 is provided with a plurality of cutting, teeth 13 of conventional design. Mounting brackets 14 are securely mounted on the outside side walls 16 of bucket 12 by any suitable means such as a plurality of bolts 18. Mounting brackets 14 (FIG. 4) are provided with angled locking flanges 19 adapted to snugly engage the leading edges of bucket walls 16 to securely anchor the brackets with respect to the bucket. The brackets are provided with spaced hinge barrels 20. adapted for alternate engagement with spaced hinge bar-- rels 22 on cutter blades 10. The blades 1'0v are pivotally mounted on brackets 14 by pivot pins 24 mounted in the aligned hinge barrels of the two parts.

As. clearly shown in FIG. 4, the blades 10 are securely fixed in any one of several different angular positions with respect to the bucket 12 by means of spacer members 26 mounted between opposing flanges 28 and 30 on blades 10 and brackets 14, respectively. The blades,

brackets and spacer are held securely together as a unit in the desired position by adjusting bolts 32 which pass through aligned openings in flanges 28, 30 and spacers 26.

To insure that bolts 32 will be pulled up snugly by nuts 34 Without binding, the holes in the flanges and spacer are elongated slightly and countersunk as at 36 (on flanges 28, 30) to form seats for semi-spherical fittings 38 mounted at each end of the bolt. With this arrangement it will be seen that as blades are adjusted from one angular position to another (by using different sized spacers) the bolts will pull up tightly without binding to securely fix the blades in all adjusted positions.

As shown in FIG. 1, each cutter blade 10 is providedwith a pair of cutting points 40 spaced at the outer extremities of a vertical cutting edge 41. A spaced deflector portion 42 is provided for each cutting point 40 and is located rearwardly of such points. Points 40 serve to cut and loosen the ground as the bucket is pulled in its cutting stroke by the back hoe. Deflector portions 42 serve to guide the loosened dirt into the bucket. With this arrangement, almost all the dirt cut from the sides of the ditch by points 40 will be .forced into the bucket to thereby reduce the time it takes to remove the dirt from the ditch.

It will be appreciated that most of the cutting will be done by the lower cutting points 40 on each blade as the bucket is pulled downwardly towards the cab of the back hoe during operation of the machine. The lower cutting points 40, therefore, will receive far greater wear than the upper cutting points which do very little cutting in normal operation. of blades 10 they are adapted for reverse mounting on opposite sides of the bucket. Thus, when one set of points on the blade wears out the blades are disconnected from brackets 14 (by removing pins 24) and remounted on opposite sides of the bucket in an inverted position so that the relatively unused cutting points 40 and deflector portions 42 will occupy the lower cutting position formerly occupied by the worn points and deflectors.

When the second set of points and deflectors is worn out, a new set of blades is installed on brackets 14, it being unnecessary to replace the brackets.

From the foregoing it will be seen that a single bucket equipped with a single pair of cutter blades ltlis capable of cutting ditches of a number of different widths. To switch from one ditch size to another can be quickly and easily accomplished by removing adjusting bolts 32 and installing a different size spacer 26 between the flanges of the blades and brackets. Spacers 26 are of predetermined thickness to provide standard ditch sizes required for different size pipes. Two or more spacers can be used together for the smaller size ditches. spacers are removed for a cut of maximum width.

It should be noted that brackets 14 are mounted on the outside walls of the bucket 12 and that blades 10 are mounted flush with the inside surface of the walls and angle outwardly from the front edges of the bucket opening. This arrangement provides a smooth, unobstructed bucket opening to facilitate the discharge of dirt therefrom as well as a smooth entry into the bucket on the cutting stroke.

Cutting points 40 and cutting edges 41 will cut straight, smooth walls on a straight-line pull. However, when desired a curved wall for a manhole can be cut by properly pivoting the machine during the cut. This type of job is normally done with the blades 10 set at the maximum cutting angle. Manhole excavation is normally done with manually operated air spades and thus this feature of the invention results in a substantial reduction in time and labor.

Finally, it is noted that by spacing cutter blades 10 All To appreciably lengthen the life 4 from bucket teeth 13 a ditch 43 such as that shown in FIG. 5 can be cut. The bottom of the ditch has unexcavated portions 44 due to the vertical spacing between the bucket teeth and the lower cutting points 40 of the blades. A ditch of such configuration is desirable ,due to savings in the amount of fill 46 required to space a pipe '48 from the bottom '50 of the ditch, since no till will be required to fill unexcavated portions 44 which would otherwise have to be filled with a conventional flat bottom ditch. It will be appreciated that if it is desired to cut a flat bottom ditch, blades 10 could be readily adapted for vertical adjustment on brackets 14 so that cutting points 40 could be set at the same level as bucket teeth 13. Such adjustment could be accomplished by providing flanges 28 of blades 10 with additional openings for adjustment bolts 32 so that the blades could be mounted on the brackets at different vertical positions. All spaces between hinge barrels 22, 28) on the blades and brackets would be equal to facilitate such vertical adjustment.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from facilitate making cuts of diflerent Widths without changing buckets or replacing the cutter blades, said cutter blades each having two spaced cutting points, said blades each being of symmerical configuration about their transverse axes to facilitate reversal of said blades from one side of the bucket to the other so that when one cutting point of the blade becomes worn the other cutting point of each blade can be put into use by reversing and inverting the blades.

2. A cutter attachment according to claim 1 in which each of said blades has a deflector portion thereon located rearwardly from sad cutting points and operable to guide the dirt cut by the points into the bucket.

3. A cutter attachment for an excavating bucket comprising, a pair of mounting brackets adapted to be fixedly secured to opposite sides of the bucket, a pair of cutter blades mounted on said brackets and adapted for making a cut having a width in excess of the bucket with, said cutter blades being mounted parallel to and at the leading edge of the bucket side walls and adjusting means for adjusting the position of said blades with respect to said brackets to facilitate making cuts of different widths without changing buckets or replacing the cutter blades, said adjusting means including mating hinge barrels on said blades and brackets, a hinge pin mounted in said barrels, opposing flanges on said blades and brackets, a plurality of adjustment bolts passing through said opposing flanges to securely hold the blades and brackets in the various adjusted positions, and spacer means mounted between said flanges for setting said blades in the desired aoaaaei parallel to and at the leading edge of the bucket side Walls, and adjusting means for adjusting the position of said blades with respect to said brackets to facilitate making cuts of different widths Without changing buckets or replacing the cutter blades, said adjustment means including mating hinge barrels on said blades and brackets and a hinge pin mounted in said barrels, said adjustment means further including opposing flanges on said blades and mounting brackets, a plurality of apertures in said flanges, a plurality of adjusting bolts passing through said apertures, and spacer means mounted between said flanges for setting said blades at different angular positions with respect to the sides of the bucket.

6. A cutter attachment for an excavating bucket comprising, a pair of mounting brackets adapted to be fixedly secured to opposite sides of the bucket, a pair of cutter blades mounted on said brackets and adapted for making a cut having a width in excess of the bucket width, said cutter blades being mounted parallel to and at the leading edge of the bucket side walls, hinge means for permitting pivotal movement of said blades with respect to said brackets to facilitate making cuts of diflerent Widths without changing buckets or replacing the cutter blades, and locking means for said hinge means to lock said blades at any desired angle with respect to said brackets, said locking means including opposing flanges on said blades and mounting brackets, a plurality of apertures in said flanges, a plurality of adjusting bolts passing through said apertures, and spacer means mounted between said opposing flanges for setting said blades at different angular positions with respect to the sides of the bucket.

7. A cutter attachment according to claim 1 in which said mounting brackets have locking flanges thereon for gripping engagement with the leading edges of the bucket opening to securely anchor said brackets on the bucket.

References Cited in the file of this patent UNITED STATES PATENTS 2,113,761 Joy Apr. 12, 1938 2,556,592 Markkula June 12, 195 1 FOREIGN PATENTS 303,384 Germany Sept. 19, 1919 

5. A CUTTER ATTACHMENT FOR AN EXCAVATING BUCKET HAVING SIDE WALLS COMPRISING, A PAIR OF MOUNTING BRACKETS ADAPTED TO BE FIXEDLY SECURED TO OPPOSITE SIDES OF THE BUCKET, A PAIR OF CUTTER BLADES MOUNTED ON SAID BRACKETS AND ADAPTED FOR MAKING A CUT HAVING A WIDTH IN EXCESS OF THE BUCKET WIDTH, SAID CUTTER BLADES BEING MOUNTED PARALLEL TO AND AT THE LEADING EDGE OF THE BUKCET SIDE WALLS, AND ADJUSTING MEANS FOR ADJUSTING THE POSITION OF SAID BLADES WITH RESPECT TO SAID BRACKETS TO FACILITATE MAKING CUTS OF DIFFERENT WIDTHS WITHOUTS CHANGING BUCKETS OR REPLACING THE CUTTER BLADES, SAID ADJUSTMENT MEANS INCLUDING MATING HINGE BARRELS ON SAID BLADE AND BRACKETS AND A HINGE PIN MOUNTED IN SAID BARRELS, SAID ADJUSTMENT MEANS FURTHER INCLUDING OPPOSING FLANGES ON SAID 